Seed coating composition

ABSTRACT

The invention pertains to a seed coating composition comprising a certain latex binder and/or graft polymer dispersant. The seed coating composition imparts good color to treated seeds, has excellent durability, and is non-sticky after application to allow for smooth flow of coated seed in planting equipment.

BACKGROUND OF THE INVENTION

The invention pertains to a seed coating compositions and moreparticularly to a seed coating composition comprising a certain latexbinder and/or certain graft polymer dispersant.

Seeds are often treated to reduce yield losses during cultivation andfor enhancing the agronomic and nutritional value of the produce. Suchtreating agents are for example fungicides, insecticides, rodenticides,nematocides, miticides or bird repellents. Furthermore, many varietiesof genetically altered crops are coming to the market. Treated and/orgenetically modified seeds must be marked in order to distinguish themfrom the untreated and unmodified seeds. The marking of seeds isparticularly beneficial for farmers who then can easily distinguish thechemically treated and modified seeds for plantings from e.g. cerealgrains for consumption.

Various seed coating ingredients therefore, have been disclosed. Forexample, U.S. Pat. No. 4,272,417 discloses a seed coating compositioncomprising a binding agent selected from the class of vinyl acrylicemulsions, partially hydrolyzed copolymers of vinyl chloride and vinylacetate, polyvinyl alcohols, polyvinyl acetates, drying oil modifiedpolyurethanes, vinyl toluene copolymer modified drying oils, 23 percentpenta soya oil alkyd, pinene polymer hydrocarbon resins, chain stoppedalkyds, chlorinated rubber, epoxy esters, acrylics, modifiedpolyacrylamides, self-curing carboxylated styrene butadiene latex,polyvinyl pyrrolidone, poly (methyl vinyl ether/maleic anhydride), vinylpyrrolidone/dimethylamino ethylmethacrylate copolymer, and vinylpyrrolidone/vinyl acetate copolymer.

U.S. Pat. No. 5,849,320 discloses an insecticidal coating for a seedcomprising one or more binders selected from the group consisting ofpolymers and copolymers of polyvinyl acetate, methyl cellulose,polyvinyl alcohol, vinylidene chloride, acrylic, cellulose,polyvinylpyrrolidone and polysaccharide and an insecticidally effectiveamount of an insecticide, wherein the binder forms a matrix for theinsecticide.

U.S. Pat. No. 4,249,343 discloses compositions for coating plant seedscomprising a water insoluble polymeric microgel that provides protectionfor the seeds from mechanical and environmental damages and that may beused as a carrier for materials such as fertilizers, herbicide,pesticides and so forth. Useful monomers for the production of microgelsby addition polymerization include acrylic acid; methacrylic acid;hydroxy esters, amino substituted esters and amides of acrylic acid,methacrylic acid and maleic acid; vinylpyridine and derivatives of vinylpyridine such as 2-methyl-5-vinylpyridine.

U.S. Pat. No. 3,707,807 discloses a composition for treating seedscomprising an aqueous emulsion of a substantially water-solubleneutralized copolymer of an α,β-unsaturated monocarboxylic acid and alower alkyl acrylate and a crosslinked copolymer of vinyl acetate and alower alkyl acrylate.

U.S. Patent Publication 2003/0221365 discloses pigment forms and pigmentconcentrates which can be effectively used for seed coloring.

Seed coating compositions and ingredients are also availablecommercially from, for example, Becker Underwood (Ames, Iowa) under theSEEDKARE® tradename, Uniqema (New Castle, Del.) under the Atlox™ Semkotetradename, International Specialty Products (Wayne N.J.) under theAgrimer® tradename and Celanese Corp. (Dallas Tex.) under the Celvol®tradename.

There is still a need for, and it is an objective of this invention toprovide, seed coating compositions that impart good color to treatedseeds, that resist attrition and dust formation on handling and that arenon-sticky and allow smooth flow of coated seed in planting equipment.

SUMMARY OF THE INVENTION

In accord with an objective of this invention, there is provided a seedcoating composition comprising an aqueous carrier, a pigment colorant,and either one or both of (a) an acrylic latex binder and/or (b) a graftcopolymer dispersant.

The acrylic latex binder is an acrylic polymer dispersion containingabout 30-40% by weight methyl methacrylate, 10-20% by weight styrene,35-45% by weight 2-ethylhexyl acrylate, 1-6% by weight methylolmethacrylamide, 1-5% by weight hydroxyethyl acrylate and 1-5% by weightmethacrylic acid; and, wherein the acid groups of the graft copolymerare neutralized with an inorganic base or an amine.

The dispersant is a graft copolymer having a weight average molecularweight of about 5,000-100,000 and comprising a polymeric backbone andmacromonomer side chains attached to the backbone wherein: (1) thepolymeric backbone is hydrophobic in comparison to the side chains andcontains polymerized ethylenically unsaturated hydrophobic monomers andup to 20% by weight, based on the weight of the graft copolymer, ofpolymerized ethylenically unsaturated acid containing monomers; and (2)the sidechains are hydrophilic macromonomers that are attached to thebackbone at a single terminal point and contain polymerizedethylenically unsaturated monomers and 2-100% by weight, based on theweight of the macromonomer, of polymerized ethylenically unsaturatedacid containing monomers and have a weight average molecular weight ofabout 1,000-30,000; and, wherein the acid groups of the graft copolymerare neutralized with an inorganic base or an amine.

The prescribed acrylic latex binder is particularly advantageous forproviding a durable, non-sticky coating that effectively binds colorantsand other ingredients to treated seeds.

The prescribed graft copolymer dispersant is particularly effective atstably dispersing a range of pigment colorants in an aqueous seedcoating carrier comprising binder. Because of the advantageousdispersion properties of the prescribed graft copolymer dispersant, agiven color strength can be achieved with less pigment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Seed Coating Composition

Seed coating compositions comprise an aqueous carrier which can besimply water, or combination of water and other solvent(s), and colorantdispersed or dissolved in the carrier. The composition will typicallycomprise binder, such as a polymer or resin, dispersed or dissolved inthe carrier. The will also typically comprise colorant, especiallypigment colorant, and also may comprise a dispersant, such as a polymeror resin dispersant, to stabilize the dispersion of a pigment colorant.Other ingredients known in the art may also be present in thecomposition including, for example, surfactants, biocides, fungicides,insecticides, fillers and the like.

The seed coating composition according to the present invention willcomprise one or both of a prescribed latex binder and/or a prescribedgraft copolymer dispersant which species are herein after described.Although not limited to any particular amounts, seed coatingcompositions will generally contains 0.01 to 10 wt % pigment, and 40 to98 wt % aqueous carrier. When the prescribed dispersant is present, thepigment to dispersant weight ratio will generally be in the range ofabout 0.1/100 to 1500/100. When the prescribed acrylic latex binder ispresent, it will generally be present in an amount of between about 0.5and 40 wt % (polymer solids basis). All percentages are weight percent(wt %) of the ingredient relative to the final weight of seed coatingcomposition.

Colorant

Seed coatings typically comprise colorant so as to be visuallydistinguishable. Suitable colorants include charcoal, graphite, ironoxide, tartrazine, titanium dioxide, zinc oxide and organic pigmentswith C.I. designation Pigment Blue 15, Pigment Green, Pigment Violet 23and Pigment Red 48. Suitable colorants can also include dyes such asthose with C.I. designation Food Red 17, Food Blue 2, Solvent Green,Solvent Red 23, Acid Red 33, Solvent Violet 13, and Basic Blue 9. The“C.I.” designation refers to the nomenclature established by SocietyDyers and Colourists, Bradford, Yorkshire, UK and published in The ColorIndex, Fourth Edition, 2002.

Binder

A binder can be any suitable binder approved for agricultural use, Onesuch list of suitable binders can be found in the U.S. Code of FederalRegulations Title 40, Part 180.960 (referred to hereafter as 40CFR180.960).

Included in this list approved binders are acrylic polymers composed ofone or more of the following monomers: acrylic acid, methyl acrylate,ethyl acrylate, butyl acrylate, hydroxyethyl acrylate hydroxybutylacrylate, carboxyethyl acrylate, methacrylic acid, methyl methacrylate,hydroxy butyl methacrylate, lauryl methacrylate, and stearylmethacrylate; with none and/or one or more of the following monomers:acrylamide, N-methyl acrylamide, N,N-dimethyl acrylamide, N-octylacrylamide, maleic anhydride, maleic acid, monoethyl maleate, diethylmaleate, monooctyl maleate, dioctyl maleate; and their correspondingsodium, potassium, ammonium, isopropylamine, triethylamine,monoethanolamine, and/or triethanolamine salts. Other suitable bindersfrom this list include: copolymers of methyl vinyl ether with maleicanhydride or monoalkyl esters of maleic anhydride (e.g. Agrimer® VEMAline of products from ISP); polyvinylpyrrolidone; copolymers of vinylpyrrolidone with vinyl acetate (e.g., Agrimer VA line of products fromISP); copolymers of vinyl pyrrolidone with vinyl alkyls (e.g. Agrimer®AL line of products from ISP); polyvinyl acetate; ethylene/vinyl acetatecopolymers (e.g. Atlox® SemKote E product line from Uniqema); vinylacetate acrylic copolymers (e.g., Atlox® Semkote V product line fromUniqema); A-B block copolymers of ethylene oxide and propylene oxide;A-B-A triblock copolymers of EO-PO-EO (e.g. Pluronics® line from BASF);and polyvinyl alcohol.

A preferred binder is an acrylic latex polymer comprising N-methylol(meth)acrylamide monomer. The term “latex” as used herein means adispersion in an aqueous carrier of polymer particles having a particlesize of about 0.06-0.20 microns and a weight average molecular weight ofgreater than 500,000. (typically 500,000 to about 3,000,000)

A particularly preferred acrylic latex binder polymer comprises: anacrylic polymer containing about 30-40% by weight methyl methacrylate,10-20% by weight styrene, 35-45% by weight 2-ethylhexyl acrylate, 1-6%by weight methylol methacrylamide, 1-5% by weight hydroxyethyl acrylateand 1-5% by weight methacrylic acid which binder is described in U.S.Pat. No. 5,219,916, which disclosure is incorporated by reference hereinfor all purposes as if fully set forth.

The acrylic latex polymer is formed by conventional emulsionpolymerization by emulsifying a mixture of monomers, water, surfactantand polymerization catalyst and charging the resulting emulsion into aconventional polymerization reactor and heating the constituents in thereactor to about 60-95° C. for about 15 minutes to 8 hours and then theresulting polymer is neutralized with ammonia or an amine. The size ofthe polymeric particles of the latex is about 0.06-0.20 microns. Theresulting polymer has a hydroxyl no. of 2-100, a glass transitiontemperature of −40 to +40° C. and a weight average molecular weight ofabout 500,000-3,000,000.

All molecular weights herein are measured by gel permeationchromatography using polystyrene as the standard.

Typically useful catalysts are ammonium persulfate, hydrogen peroxide,sodium meta bisulfite, hydrogen peroxide, sodium sulfoxylate and thelike.

Typically useful surfactants are nonylphenoxypolyethyleneoxy ethanolsulfate, allyl dodecyl sulfosuccinate, alkyl phenoxy polyethyleneoxyethanol, sodium lauryl sulfate and mixtures thereof. One preferredsurfactant is a mixture of nonylphenoxy polyethyleneoxy ethanol sulfateand allyl dodecyl sulfosuccinate.

The acrylic latex polymer contains about 1-15% by weight of polymerizedmethylol methacrylamide, methylol acrylamide or any mixtures thereof.

Dispersant

Pigment dispersion stability in aqueous carrier can be increased by thepresence of a polymer dispersant or surfactant. Suitable dispersants andsurfactants include those commonly used in agricultural and cropprotection applications such as those listed in the Code of FederalRegulations Title 40 Parts 180.900, 180.910, and 180.920 (to be referredto hereafter as 40CFR 180.900; 40CFR 180.910; and 40 CFR 180.920,respectively.) That list includes, for example, A-B block copolymers ofethylene oxide and propylene oxide; A-B-A triblock copolymers ofEO-PO-EO (e.g. Pluronics® line from BASF); naphthalenesulfonicacid-formaldehyde condensates, ammonium and sodium salts; styrene-maleicanyhydride copolymers; monobutyl/ethyl Ester of poly(methyl vinylether/maleic acid), partial sodium salt (e.g. EasySperse Dispersantavailable from ISP); methyl methacrylate/polyethylene glycol graftcopolymer (e.g. Atlox 4913 from Uniqema); random, water-soluble acryliccopolymers (e.g. Metasperse 100L and Atlox® 4914 from Uniqema); nonylphenol ethoxylates (e.g. Tergitol nonionic surfactants from DowChemical); octyl phenol ethoxylates (e.g. Triton nonionic surfactantsfrom Dow Chemical and Igepal product line from Stepan Chemical).

A preferred dispersant is a graft copolymer having a weight averagemolecular weight of about 5,000-100,000 and comprising a polymericbackbone and macromonomer side chains attached to the backbone and morespecifically a graft copolymer dispersant wherein:

(1) the polymeric backbone is hydrophobic in comparison to the sidechains and contains polymerized ethylenically unsaturated hydrophobicmonomers and up to 20% by weight, based on the weight of the graftcopolymer, of polymerized ethylenically unsaturated acid containingmonomers; and

(2) the sidechains are hydrophilic macromonomers that are attached tothe backbone at a single terminal point and contain polymerizedethylenically unsaturated monomers and 2-100% by weight, based on theweight of the macromonomer, of polymerized ethylenically unsaturatedacid containing monomers and have a weight average molecular weight ofabout 1,000-30,000 and wherein the acid groups of the graft copolymerare neutralized with an inorganic base or an amine.

The graft copolymer contains about 50-90% by weight of polymericbackbone and correspondingly about 10-50% by weight of sidechains. Thegraft copolymer has a weight average molecular weight of about5,000-100,000 and preferably about 10,000-40,000. The side chains of thegraft copolymer are formed from hydrophilic macromonomers that have aweight average molecular weight of about 1,000-30,000 and preferably2,000-5,000 and contain about 2-100% by weight and preferably 20-50% byweight, based on the weight of the macromonomer, of polymerizedethylenically unsaturated acid monomers. These sidechains arehydrophilic and keep the dispersant and pigments uniformly dispersed inthe pigment dispersion and in the resulting coating composition.

The backbone of the graft copolymer is hydrophobic relative to thesidechains and may contain up to 20% by weight, preferably 1-10% byweight, based on the weight of the graft copolymer, of polymerizedethylenically unsaturated acid monomers which are listed hereinafter.The backbone contains polymerized hydrophobic monomers such as alkylmethacrylates and acrylates, cycloaliphatic methacrylates and acrylatesand aryl methacrylates and acrylates as are listed hereinafter and alsomay contain up to 30% by weight, based on the weight of the graftcopolymer, of polymerized ethylenically unsaturated non-hydrophobicmonomers which may contain functional groups. Examples of such monomersare hydroxy ethyl acrylate, hydroxy ethyl methacrylate, t-butylaminoethyl methacrylate, diethyl amino ethyl acrylate, diethyl amino ethylmethacrylate, acrylamide, nitro phenol acrylate, nitro phenolmethacrylate, phthalimido methyl acrylate, phthalimido methacrylate,acrylic acid, acryloamido propane sulfonic acid.

The backbone of the graft copolymer has an affinity for the surface ofthe pigment used in the dispersion and anchors the copolymer to thepigment and keeps the pigment dispersed and prevents the graft copolymerfrom returning to the aqueous phase. Reactive groups on the backbone canreact with the pigment and form a bond with the pigment.

Molecular weights are determined by Gel Permeation Chromatography usingpolystyrene as a standard.

The macromonomer contains a single terminal ethylenically unsaturatedgroup which is polymerized into the backbone of the graft copolymer andprimarily contains polymerized monomers of methacrylic acid, its esters,nitriles, amides or mixtures of these monomers.

Typical alkyl methacrylates that can be used have 1-8 carbon atoms inthe alkyl group and are for example methyl methacrylate, ethylmethacrylate, propyl methacrylate, isopropyl methacrylate, butylmethacrylate, pentyl methacrylate, hexyl methacrylate, 2-ethyl hexylmethacrylate and the like. Cycloaliphatic methacrylates also can be usedsuch as trimethylcyclohexyl methacrylate, isobutylcyclohexylmethacrylate, and the like. Aryl methacrylates also can be used such asbenzyl methacrylate. Other polymerizable monomers that can be used arestyrene, alpha methyl styrene, methacrylamide and methacrylonitrile. Theabove monomers can also be used in the backbone of the graft copolymer.

The macromonomer can contain 2-100% by weight, preferably about 20-50%by weight, based on the weight of the macromonomer, of polymerizedethylenically unsaturated acid. Methacrylic acid is preferredparticularly if it is the sole constituent. Other acids that can be usedare ethylenically unsaturated carboxylic acids such as acrylic acid,itaconic acid, maleic acid and the like. Ethylenically unsaturatedsulfonic, sulfinic, phosphoric or phosphonic acid and esters thereofalso can be used such as styrene sulfonic acid, acrylamido methylpropane sulfonic acid, vinyl phosphonic acid and its esters and thelike. The above acids also can be used in the backbone of the graftcopolymer.

Up to 40% by weight, based on the weight of the macromonomer, of otherpolymerized ethylenically unsaturated monomers can be present in themacromonomer. Primarily alkyl acrylates having 1-12 carbons in the alkylgroup can be used such as methyl acrylate, ethyl acrylate, propylacrylate, isopropyl acrylate, butyl acrylate, pentyl acrylate, hexylacrylate, 2-ethyl acrylate, nonyl acrylate, lauryl acrylate and the likecan be used. Cycloaliphatic acrylates can be used such astrimethylcyclohexyl acrylate, t-butyl cyclohexyl acrylate and the like.Aryl acrylates such as benzyl acrylate also can be used. The abovemonomers also can be used in the backbone of the graft copolymer.

One preferred macromonomer contains about 50-80% by weight ofpolymerized methyl methacrylate and 20-50% by weight of polymerizedmethacrylic acid and has a weight average molecular weight of about2,000-5,000. To ensure the macromonomer only has one terminalethylenically unsaturated group which will polymerize with the backbonemonomers to form the graft copolymer, the macromonomer is preferablypolymerized using cobalt chain transfer agents.

Methods of making graft copolymer dispersant are known and described,for example, in U.S. Pat. No. 5,231,131 which disclosure is incorporatedby reference herein for all purposes as if fully set forth.

To form a pigment dispersion or a mill base, pigments are added to theaqueous graft copolymer dispersion and then the pigments are dispersedusing conventional techniques such as high speed mixing, ball milling,sand grinding, attritor grinding or two or three roll milling. Theresulting pigment dispersion has a pigment to dispersant binder weightratio of about 0.1/100 to 1500/100.

The preferred graft copolymer dispersant is advantageous in seedcoatings with pigment colorant because it provides good color strengthon the coated seed, therefore less pigment is needed to achieving agiven level of coloration. It also has the advantage of being able todisperse a wide range of pigments both organic and inorganic.

Coated Seeds

The seeds prescribed herein are used to grow plants, fruits, orvegetables. The particular type of seed is not critical. The coatingcomposition is applied to the exterior surface of the seeds and thewater and other volatile components are allowed to vaporize leaving thenon-volatile components bound to the seed by the binder.

Various techniques and equipment known in the seed coating art may beused for applying the coating composition to the seed. The process maybe continuous or batch and typically involves tumbling the seed in thepresence of the coating composition. Some drying of the coated seed maybe required.

It may be advantageous to “overcoat” the coated seeds with additionalbinder to encase the seed treating agents and further protect them fromattrition during handling.

The following examples illustrate the invention without, however, beinglimited thereto.

EXAMPLES

Preparation of Graft Copolymer Dispersant

Using the methods described in U.S. Pat. No. 5,231,131 a macromonomerwas prepared with contained 28.75% methacrylic acid and 71.25% methylmethacrylate and having a weight average molecular weight of about 4000and a number average molecular weight of about 2000.

Graft Copolymer 1 was prepared by polymerizing the macromonomer abovewith butyl acrylate, methyl acrylate and acrylic acid, again followingthe methods described in U.S. Pat. No. 5,231,131 and having the overallapproximate composition: 31.8% butyl acrylate, 31.8% methyl acrylate,6.4% acrylic acid, 21.4% methyl methacrylate, and 8.6% methacrylic acidand had a weight-average molecular weight of about 24000 and anumber-average molecular weight of about 9500. Graft copolymer 1 wasneutralized with 2-amino-2-methyl-1-propanol and recovered as a 30 wt %solution in water for subsequent use as a dispersant.

Preparation of Latex Binder

Latex Binder 1 was prepared according to methods described in U.S. Pat.No. 5,219,916 having the following monomer composition:MMA/S/2-EHA/MOLMAM/HEA/MAA in a weight ratio of 26.5/15/50/2.5/3/3. Itwas neutralized with ammonia to form the ammonium salt and had a weightaverage molecular weight of about 500,000-1,250,000. Latex 1 had aaverage particle size was 0.095 microns and was recovered as an aqueousslurry with 35.7 wt % polymer solids. The following abbreviations areused for the monomers: MMA is methyl methacrylate; S is styrene; 2-EHAis 2-ethylhexyl acrylate; MOLMAM is N-methylol methacrylamide; HEA ishydroxyethyl acrylate; and MAA is methacrylic acid.

Example 1

Dispersion 1 was prepared from 100 parts of Latex Binder 1 describedabove, 3 parts of talc and 0.5 parts of Pigment Red 48:2. Ingredientswere mixed and milled in a sand mill with 0.8-1.0 mm zirconia media. Themilled dispersion had a Brookfield viscosity (Brookfield viscometer, #3spindle, 100 rpm, 25° C.) of 197 cps and a pH of 5.51. As demonstratedhere, low concentration of pigment, about 0.5 wt %, can form anadequately stable dispersion in the latex binder solution withoutseparate dispersant. However, higher concentrations of pigment (2-4 wt%) would not disperse adequately, and dispersant was required.

Coating Composition 1 was prepared by stirring together three fluid oz.of Dispersion 1, 10 fluid oz of Prescribe® insecticide (trademark ofGustafson), 2 additional oz of water and isopropyl alcohol (0.5% wt %based on total weight of the coating composition.

Coating Composition 1 was applied to corn seed at a rate of 3 fluid ozof the coating composition per 100 pounds of seed, whereafter the seedwas allowed to dry at ambient temperature. As judged by visualinspection and routine handling, the dried seeds were uniformly coatedand the coating felt durable and non-sticky.

Example 2

Dispersion 2 was prepared from 100 parts of Latex Binder 1, one partethylene glycol monobutyl ether and 0.5 parts of Pigment Violet 23 inthe same manner as described for Dispersion 1. This demonstrates aviolet colored composition, again with a low concentration of pigmentand no dispersant. As with dispersion 1, higher concentrations ofpigment required dispersant for adequate dispersion quality.

Example 3

Dispersion 3 was prepared by mixing, in order 198.2 parts of deionizedwater, 142.2 parts of Graft Copolymer 1 solution, 33.3 parts of LatexBinder 1 and 6.7 parts of Surfynol® 104 DPM (surfactant from AirProducts, Allentown, Pa., USA). When these ingredients were thoroughlymixed, 133.4 parts of Pigment Violet 23 was added, slowly, after whichthe mixture was stirred under high shear with a high speed disperser.Another 20.5 gms deionized water was added and the mixture wastransferred to a Eiger mill and milled with 0.6-0.8 mm zirconia grindingmedia. At the end of the milling cycle another 126.7 parts of deionizedwater was added, followed by another brief period of milling. Afterfiltration through 5 micron paper, the dispersion had a viscosity(Brookfield viscometer, UL adapter, 25° C.) of 28.3 cps and a pH of 7.5.

Coating Composition 3 (containing 4 wt % PV 23) was prepared by mixing,in order, 199.4 parts of Dispersion 3, 10 parts of butyl cellosolve and790.6 parts of Latex Binder 1. After straining through a 250 micronpaint strainer, the resulting coating composition had a viscosity(Brookfield viscometer, RV#2 Spindle, @100 rpm, 25° C.) of 97 cps, and apH of 8.56. In the presence of graft copolymer dispersant, stable, highpigment content compositions were achieved.

Example 4

Coating composition 4 was prepared from 43.9 parts of Dispersion 4 fromExample 4, 2.2 parts butyl cellosolve, 2.2 parts Surfynol® 104 BC(surfactant from Air Products), and 171.7 parts Latex Binder 1 in amanner a similar Coating Composition 3 in the previous example. Thismixture was stirred with Poncho 1250 to make the final composition.Coating composition 5 was applied to hybrid seed corn at a rate of 1.5fluid oz./100 pounds of seed. The coated seed had very good appearance(even coating, stronger color).

Example 5

Coating Composition 5 was prepared from 43.87 parts of Dispersion 3, 2.2parts butyl cellosolve, 2.2 parts Surfynol 104 BC, and 171.7 parts LatexBinder 1 in a manner a similar Coating Composition 3 in the Example 3.This mixture was stirred with was mixed with Poncho 1250 to make thefinal composition. Coating composition 5 was applied to hybrid seed cornat use rates of 1.5 fluid oz./100 pounds of seed. The coated seed hadvery good appearance (even coating, stronger color).

Example 6

Dispersion 6 was prepared by mixing, under low shear, 255.8 parts ofdeionized water, 111.2 parts of Graft Copolymer 1, 33.3 parts of LatexBinder and 6.7 parts of Surfynol® 104 DPM (surfactant from AirProducts). To the mixture was added, slowly, 133.4 parts of Pigment Red48:2. After the pigment addition was complete, the mixture was stirredunder high shear with a high speed disperser. Another 101.6 parts ofdeionized water was added and the mixture was transferred a sand milland milled with 0.6-0.8 mm zirconia grinding media. At the end of thegrind cycle another 25.1 parts of deionized water was added, followedanother 15 minutes of grinding and discharge of the batch. Afterfiltration through 5 micron filter paper, the resulting dispersion had aviscosity (Brookfield viscometer, 00 Spindle at 100 rpm, 25° C.) of 192cps and a pH or 7.81

Application of Treated Seed

Coated seeds as disclosed in the examples herein before were planted intest plots and an assessed for germination. The germination of thecoated seeds was a good as or better than control samples. Also, thecoated seeds handled well in the application equipment in that theyresisted dust formation and flowed well without sticking.

1. A seed coating composition comprising an aqueous carrier, a pigmentcolorant, a graft copolymer dispersant, and at least one of a fungicide,an insecticide, a rodenticide, nematocide or bird repellent, wherein:the dispersant is a graft copolymer having a weight average molecularweight of about 5,000-100,000 and comprising a polymeric backbone andmacromonomer side chains attached to the backbone, wherein: (1) thepolymeric backbone is hydrophobic in comparison to the side chains andcontains polymerized ethylenically unsaturated hydrophobic monomers andpresent up to 20% by weight, based on the weight of the graft copolymer,of polymerized ethylenically unsaturated acid containing monomers; and(2) the sidechains are hydrophilic macromonomers that are attached tothe backbone at a single terminal point and contain polymerizedethylenically unsaturated monomers and 2-100% by weight, based on theweight of the macromonomer, of polymerized ethylenically unsaturatedacid containing monomers and have a weight average molecular weight ofabout 1,000-30,000; and wherein the acid groups of the graft copolymerare neutralized with an inorganic base or an amine.
 2. A method ofcoating seeds comprising mixing seed with a coating compositionaccording to claim 1 and optionally drying the seed to remove theaqueous carrier.
 3. A coated seed formed by a method comprising mixingseed with a seed coating composition comprising an aqueous carrier, apigment colorant and a graft copolymer dispersant, wherein thedispersant is a graft copolymer having a weight average molecular weightof about 5,000-100,000 and comprising a polymeric backbone andmacromonomer side chains attached to the backbone, wherein: (1) thepolymeric backbone is hydrophobic in comparison to the side chains andcontains polymerized ethylenically unsaturated hydrophobic monomers andpresent up to 20% by weight, based on the weight of the graft copolymer,of polymerized ethylenically unsaturated acid containing monomers; and(2) the sidechains are hydrophilic macromonomers that are attached tothe backbone at a single terminal point and contain polymerizedethylenically unsaturated monomers and 2-100% by weight, based on theweight of the macromonomer, of polymerized ethylenically unsaturatedacid containing monomers and have a weight average molecular weight ofabout 1,000-30,000; and wherein the acid groups of the graft copolymerare neutralized with an inorganic base or an amine.
 4. The coated seedof claim 3 further comprising at least one of a fungicide, aninsecticide, a rodenticide, nematocide, miticide or bird repellent.